Laci Peterson was pregnant when she vanished. Her husband is now accused of killing her and their child

Authorities declined to comment on reports that Laci's body was headless (ruling out identification by dental records) and missing limbs (no fingerprints), but the California department of justice DNA lab says it did not receive any tooth samples. Ronald Singer, president-elect of the American Academy of Forensic Sciences, says the lack of a head would not automatically mean it was removed by a killer. "Through the natural decomposition process, the head can become severed from the body," he says. "Or she may have been tethered in some way around the neck, with cement blocks or chains, to keep her underwater." It is also unclear how Conner's body became separated from Laci's, but one possibility is "coffin birth," the expulsion of the fetus during the decomposition of the mother.

While analysts were working through the night to make a DNA match, Modesto police-department detectives were tracking the whereabouts of Scott, who had dyed his hair lighter, had grown a goatee and was in San Diego, where his parents live. Concerned that Scott might flee across the border to Mexico, officials arrested him even before the tests were completed. Last weekend Scott's lawyer stuck a NO MEDIA sign on his door and did not return phone calls. He'll need to do plenty of talking once his client stands trial for capital murder. --With reporting by Laura A. Locke/San Francisco